There has been known an inkjet printer, which is an example of a droplet ejection device, that ejects ink from an aperture (ejection opening) of a nozzle in fluid communication with a pressure chamber by applying pressure to ink in the pressure chamber through driving of piezoelectric or electrostatic actuator. Also, there is known a tone control, in which an ink amount for each pixel of an image is selected from among a plurality of different amounts (zero (no ejection), small, medium, and large amounts, for example).
However, because of the effect of ejection history, there is a danger that ink is not ejected by a desired amount or in a desired direction. At worst, no ink may be ejected at all. In order to suppress such ejection instability, there has been proposed to determine, on an image pixel basis, an ejection amount of ink in a recording cycle based on ejection amounts of ink in preceding and following recording cycles.